Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Explain adverse effects of emtricitabine, Explain Adverse effects of Emtric...

Explain Adverse effects of Emtricitabine  Emtricitabine can cause hyperpigmentation of the palms and soles, particularly in dark-skinned patients. Because emtricitabine is also

Nutrition, define alimentary canal

define alimentary canal

Polyarthritis, It is the most common (occurring in 75 per cent cases of ARF...

It is the most common (occurring in 75 per cent cases of ARF) manifestation of ARF. It involves large joints, it is typically fleeting in character shifting from one large joint t

Can you explain lane and eynon method, Q. Can you explain Lane and Eynon me...

Q. Can you explain Lane and Eynon method? Reducing sugars are those, which have free sugar groups (e.g. glucose, fructose etc.) and hence may be estimated directly by titrat

Style of stigma interaction, Style of Stigma Interaction The style has...

Style of Stigma Interaction The style has been distinguished into two types: In open styles a stylar canal is present which is lined with a well-developed glandul

Define biogeographic realm, Q. Define biogeographic realm? Biogeographi...

Q. Define biogeographic realm? Biogeographic regions are large areas that contain characteristic assemblages of animals and plants, d elineated on account of natural barriers s

Multiple replicons , In the eukaryotes replication of chromosomal DNA happe...

In the eukaryotes replication of chromosomal DNA happens only in the S phase of the cell cycle. As for bacterial DNA, eukaryotic DNA is replicated     figure: The euk

Use the relationships for temperature conversions, The °C and °F scales are...

The °C and °F scales are equivalent at only one temperature. That is, x °C = x °F. Use the relationships for temperature conversions to DERIVE (FIND) that temperature. This problem

Zoology, Wheel organ of amphioxus.

Wheel organ of amphioxus.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd